There are plenty more 'heavy hitters' that can be made than just Capt Marvel, Plastic Man, and Firestorm... They can easily come out with those now and still have plenty of juice for more waves... As far as heavy hitters go we can still get...
Isis - maybe it's just my generation, but to me she's an icon, even is she wasn't on the show
Black Lightning - Say what you want, but most of y'all have mentioned him plenty, so I'd say he's got some selling power
Power Girl - If her comic sales are any indication of the collector market for her, she'll be fine
Cyborg - Was also a Super Powers figure and could def sell well considering his ebay price for his figure
Capt. Atom, Blue Bettle, Question, - yeah the license is difficult, but there is money to be made there
Wonder Twins - Come on, we all secretly want them! I know you do, and EVERYONE knows who they are
Besides, excluding Joker and Hawkman who are in the newest wave, basically the last couple waves haven't had anyone extremely iconic or heavy hitter esque... Not anymore so than these or anyone else we want made anyway, so why spread out?
We've gotten:
Volcana
Obsidian
Vigilante
Deadshot
Sand
Star Sapphire
Stargirl
Parasite
Blue Devil
Big Barda

Personally, I think BlackHawk is a stretch in terms of characters I want to see...I may be in the minority, but I would much rather fill out the JLU ranks....
Vibe, Commander Steel, Gypsy, Mr Terrific, Dr Midnight, Hourman, Johnny Thunder, Thunderbolt, Crimson Avenger, Crimson Fox and STRIPE.

After that, there are a ton of Secret Society people I would like...too many to count...

Blackhawk does absolutely nothing for me at all. If Blakhawk is a single, I will probably pass on the figure. I would however like to see Jonah Hex made into a figure. I agree that I wouldn't mind the Wonder Twins, but i draw that line at Wendy and Marvin.

Personally, I think BlackHawk is a stretch in terms of characters I want to see...I may be in the minority, but I would much rather fill out the JLU ranks....Vibe, Commander Steel, Gypsy, Mr Terrific, Dr Midnight, Hourman, Johnny Thunder, Thunderbolt, Crimson Avenger, Crimson Fox and STRIPE.

After that, there are a ton of Secret Society people I would like...too many to count...

I agree with all of that. Blackhawk would be cool, but not a high priority. But this got me thinking, why Blackhawk over Sgt Rock and Easy Company?

- He had multiple appearances (sure he didn't talk but neither did obsidian)
- he is on the "approved list" but is basically (from the neck down) the question in red. therefore when question becomes available rights wise its well inside the mattel budget (it would just be a new head on a rehashed body)